An air carrier dispatcher reported that the company flight planning computer used unrealistic parame...

Narrative:

This flight was dispatched with alternate ont. The flight planning computer showed the fuel burn from missed approach lax to ont as 1;687 pounds and 11 minutes at FL370. First; this airplane cannot make it to FL370 at this planned weight at lax. Second; the aircraft could not climb from missed approach to FL370 and descend back down in 11 minutes. This is not in any way possibly. I have reviewed some other fights that have also been planned with ont as an alternate and they; too are being planned at an altitude that is not feasible. Correct the flight planning computer to reflect actual conditions based on aircraft true performance and actual ATC conditions.

Original NASA ASRS Text

Title: An Air Carrier Dispatcher reported that the Company flight planning computer used unrealistic parameters while calculating fuel for a flight to LAX with ONT as an alternate. The computed alternate flight was 11 minutes at FL370.

Narrative: This flight was dispatched with alternate ONT. The flight planning computer showed the fuel burn from missed approach LAX to ONT as 1;687 LBS and 11 minutes at FL370. First; this airplane cannot make it to FL370 at this planned weight at LAX. Second; the aircraft could not climb from missed approach to FL370 and descend back down in 11 minutes. This is not in any way possibly. I have reviewed some other fights that have also been planned with ONT as an alternate and they; too are being planned at an altitude that is not feasible. Correct the flight planning computer to reflect actual conditions based on aircraft true performance and actual ATC conditions.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	902407
Time
Date	201007
Local Time Of Day	0001-0600
Place
Locale Reference	ONT.Airport
State Reference	CA
Aircraft 1
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	Parked
Flight Plan	IFR
Person 1
Function	Dispatcher
Qualification	Dispatch Dispatcher
Events
Anomaly	Deviation - Procedural FAR Deviation - Procedural Published Material / Policy Inflight Event / Encounter Fuel Issue

An air carrier dispatcher reported that the company flight planning computer used unrealistic parameters while calculating fuel for a flight to lax with ont as an alternate. The computed alternate flight was 11 minutes at FL370.